Path4gmns

v0.8.6 fixes crucial bugs related to the column generation module and greatly enhances the parsing functions. A full list of addressed issues can be found [here](https://github.com/users/jdlph/projects/1).

v0.8.6a2 is a **_hotfix_** to v0.8.6a1 over the bug in _output_equity() where only one line was output.

v0.8.6a1 comes as a **_hotfix_** to v0.8.5 over the following two issues.

1. read_nodes() cannot proceed if a record of column "is_boundary" is empty or nonmetric.
2. misleading code snippet in finding shortest paths when link sequence is expected, where the key word "seq_type" should have been placed before argument 'link'.

Other updates include

1. separate _output_equity() from evaluate_accessibility();
2. optimize the setup for bin_index in read_nodes() and polish README on Synthesize Zones and OD Demand.

1. remove legacy namings inherited from dtalite_s.py;
2. remove useless (legacy) members;
3. remove useless imports automatically added by VS Code;
4. change the value of MAX_LABEL_COST to the largest integer (i.e., 2147483647);
5. change the caller of setup_spnetwork() from read_network() to perform_column_generation();
6. introduce class Zone and update the previous implementation where involves zones accordingly;
7. support loading demand for an agent type and a demand period via load_demand();
8. support loading zone information after synthesis;
9. update all settings.yml in data directory to include "use_link_ffs".

1. fix bug in mean accessibility evaluation;
2. introduce special event with affected links and capacity reduction ratios, which will be considered in the process of column generation for traffic assignment.

v0.8.3 adds transportation equity evaluation besides enhancement in evaluating accessibility.

1. evaluate equity given a time budget and a segmentation of zones.
2. add use_link_ffs for each agent in settings.yml, which enables the following choice in computing accessibility.
3. choose either the free speed of an agent specified in settings.yml or the link free flow speed defined in link.csv in accessibility evaluation (and equity evaluation as well).